Precision-milled parts for micropositioning systems

21.11.2013

From uncompromising striving for precision to perfection, or: Why Märzhäuser Wetzlar relies primarily on CNC high-performance machining centres from Hermle for the production of its high-precision micropositioning system parts.

Märzhäuser Wetzlar GmbH & Co. KG, maximum accuracy is always in focus! That refers not only to microscope tables, measurement tables, control units, operating controls and motorized fine focusing, but also complete systems such as automated handling systems. The foundations were laid by brothers Heinz and Walter Märzhäuser in 1946 when they went into business independently producing precision parts for microscopy. Their international breakthrough came in 1962 with the development of the first micro manipulator, the MM 33, which still today has the highest sales in the world. The owner-operated, high-tech operation now in its second generation employs 170 qualified employees today.

Large working area of the C 40 V machining center with X = 850 mm, Y = 700 mm and Z = 500 mm and the rigid clamping table with clamping surface 1070 x 700 mm. The table is designed for universal applications with standard and special clamping devices.

The highest standards of accuracy and quality

Managing Director Dipl.-Ing. Günter Märzhäuser spoke about the very high requirements of customers and users of microscopy systems: “We have all well known international manufacturers of microscopes as original equipment manufacturer customers. About 75% of our turnover is OEM business with these customers. The remaining 25% is in customer-specific solutions or complete systems. All products are developed and designed internally and in close collaboration with our customers and users, then manufactured in-house completely under our control. This is especially true of all the mechanical components, which are fundamental for the required precision and long-term accuracy. We see maximum production depth as indispensable for being able to ensure the precision of machining processes and thus reproducible quality. That also gives us the necessary flexibility and ability to respond to individual production of a very extensive spectrum of workpieces consisting of about 6500 living components.” Production standards are accordingly high in the relevant technologies, milling, turning and lapping with 19 CNC precision machine tools in the ultra-modern machine park, which is fine-tuned for precision, quality and performance. Since the workpieces are frequently cubic or more accurately flat cubic parts, milling/drilling/reaming/tapping make up the lion’s share of the precision machining. The word “precision” takes on a special meaning here: “We are speaking of reproducible positioning accuracy in non-air-conditioned operation in the range of less than a µm and micro differences in height in the range of less than 200 nm in machining of surface parts. There’s no room for compromises. That’s why we have consistently relied on several Hermle CNC high-performance machining centre for precision milling since 1999 and still do today.” explains the Operations Manager of Märzhäuser Wetzlar, Volker Reinhardt (MBA).

It started in 1999 with a CNC machining centre type C 800 V, followed a year later by a type C 800 U machine and again a year later with a series C 600 V CNC machining centre. A CNC high-performance machining centre of the new C generation arrived in 2005 (a C 40 V) followed in 2012 by another C 40 V. As entioned previously, other than the CNC C 800 U machining centre, all other Hermle machines are V variants with a rigid clamping table. There are good reasons for this, as Volker Reinhardt explains: “We were literally tortured by worries about accuracy and reproducibility and we looked at different machine manufacturers before choosing Hermle after some truly impressive trial milling. The focus for us is not on complex 5-sided complete machining, but rather on highly precise complete machining of the flat workpieces described earlier.

A consistent package for users!

The main reasons for Märzhäuser Wetzlar choosing Hermle included (and still do) such factors as the modified gantry design for maximum stability and rigidity, high precision and absolutely high reproducibility as well as long-term accuracy, very high reliability, availability “off the rack”, the uniform control and operating concept, and last but not least the fast, competent customer service, ready with all relevant spare parts. “For us as in-house manufacturers with a high proportion of added value in the manufacture of micropositioning systems, it’s a very important competitive factor. That’s why we always have and will continue to build on our partnership with Hermle.”